Combine Shipping Costs?

HI
Is it possible to combine shipping on items up to a certain price point?
We ship free over $300, and have various other prices for items depending on what it is, but would like to offer the customer a combined rate of shipping when purchasing more than one item up to the point where free shipping kicks in.
Thanks

OpenCart only allows a single shipping method to be chosen, so you'll need to use a single shipping method to combine all your shipping costs into a single shipping option. You can do this with Product-Based Shipping if you have different rates for different products, or Category-Based Shipping if you have different rates on a per-category basis.

Thank you!